So a lot of people don't like the use of the word literally to mean "figuratively", but they are wrong. Literally is one of those words which changes, or reverses , meaning in context. There are others:dust, to remove, or add dust - (think forensic team or cleaner), sanction ( to allow, or disallow) etc.
In fact to use it "properly" is - to my mind worse, or redundant. I was literally walking down the street can easily be, I was walking down the street. Its of no use there.
Figuratively is not a useful word either, in fact, it is rarely used, and an ugly addition to all figurative language.
It is the East, but Juliet is not figuratively the Sun. Shakespeare's metaphor was figurative, he just didn't have to announce it.
One of the forms of figurative language is hyperbole and all these are equivalently figurative language ( and we can tell in context):
I walked a million miles.
Not a word of a lie, I walked a million miles.
Honestly, I walked a million miles.
Literally, I walked a million miles.
All of the additions in sentence 2-4 are intensifiers of the hyperbole. Literally is used in the opposite of it's standard meaning here, so is honestly, but in hyperbole you intensify the exaggeration by claiming it's truth, and literally is no more out of place than honestly ( meaning dishonestly), or Not a word of a lie ( meaning: this is a lie, or exaggeration ).
You can in all cases use all these words correctly to mean their opposite.
You need to exaggerate hugely, with hyperbole. Honestly I walked 2 miles means you did walk 2 miles, hyperbolic language works when the claims are too great to be honest ( i.e. a million when you walked two, rather than twenty when you walked two, since twenty is possible), and that is what changed the meaning of the words at the start of the sentence.